[Acetabular metastatic defect reconstruction using the modular revision support cup MRS-C]

OBJECTIVE

Stabilization of metastatic acetabular defects with a bone cement-augmented revision support cup for remobilization of oncological patients in advanced cancer stages.

INDICATIONS

Metastatic acetabular defects (Metastatic Acetabular Classification, MAC 2-4) in patients with a prognostic medium or long-term survival.

CONTRAINDICATIONS

Highly limited survival due to metastatic disease (< 6 weeks). Local bone or soft tissue infection. Primary bone tumor with curative treatment option. Advanced pelvic discontinuity. Recent wound compromising systemic therapy.

SURGICAL TECHNIQUE

Standard hip approach. Curettage of the metastatic defect and careful reaming of the acetabulum before insertion of the cup. Predrilling of the dome und flange screws before application of the bone cement through the center hole of the implant and filling of the acetabular defect. Complete insertion of the screws for compound osteosynthesis. Implant of a modular inlay or dual mobility system.

POSTOPERATIVE MANAGEMENT

Full weight bearing or mobilization with two crutches according to the level of pain. Adjuvant local radiation therapy after wound consolidation. Continuation of systemic therapy according to tumor board decision.

RESULTS

Between 2012 and 2019, we treated 14 patients with metastatic acetabular defects using the modular revision support cup "MRS-TITAN® Comfort", MRS-C, Peter Brehm GmbH, Weisendorf, Germany) at our institution. Mean Harris Hip Score improvement was 23.2 with a mean patient's survival of 9.7 months due to the reduced cancer-related prognosis; 13 of the 14 implants endured the patient's prognosis. One implant had to be removed due soft tissue defect-related periprosthetic joint infection.

Intramedullary nailing versus plate compound osteosynthesis in subtrochanteric and diaphyseal pathologic femoral fractures: a retrospective cohort study

PURPOSE

Pathologic fractures of the extremities due to carcinoma metastases require individual and patient prognosis-related stabilization procedures. Quick remobilization of the patient to restore the quality of life is of high importance, especially in the case of subtrochanteric and diaphyseal femoral fractures. In our retrospective cohort study, we evaluated intraoperative blood loss, length of operation, complication rate, and regain of lower extremity function in plate compound osteosynthesis (PCO) versus intramedullary nailing (IM) for subtrochanteric and diaphyseal pathologic fractures of the femur.

METHODS

Between January 2010 and July 2021, we retrospectively reviewed 49 patients who were treated at our institution for pathologic fractures of the subtrochanteric and diaphyseal femurs for group differences in terms of blood loss, length of operation, implant survival, and Musculoskeletal Tumor Society (MSTS) score.

RESULTS

We included 49 stabilization procedures of the lower extremity due to pathologic fractures of the proximal or diaphyseal femur, with a mean follow-up of 17.7 months. IM (n = 29) had a significantly shorter operation time than PCO (n = 20) (112.4 ± 9.4 and 163.3 ± 15.96 min, respectively). We did not detect any significant differences in terms of blood loss, complication rate, implant survival, or MSTS score.

CONCLUSION

Based on our data, pathologic subtrochanteric and diaphyseal fractures of the femur can be stabilized with IM, which has a shorter operation time than PCO, but the complication rate, implant survival, and blood loss remain unaffected.

Temporary arthrodesis through static spacer implantation in two-stage treatment of periprosthetic joint infections of the knee

OBJECTIVE

Treatment of chronic periprosthetic joint infection of the knee requires the removal of the implant and thorough debridement, with reimplantation in a second stage surgery. Intramedullary spacers can be helpful during the interval between explantation and reimplantation and provide a temporary arthrodesis which fixes the knee in extension preserving leg length and administers local antibiotic therapy.

INDICATIONS

Periprosthetic joint infection of the knee with large bony defects and severe infection of the native joint with advanced destruction/infiltration of the cartilage and bone and/or ligament insufficiency.

CONTRAINDICATIONS

Suspected antibiotic resistance of the microbiological pathogen to local antibiotic drugs, incompliant patient, and known allergy to bone cement or antibiotic.

SURGICAL TECHNIQUE

After implant removal, suitable metal rods are coated with antibiotic-loaded bone cement and inserted into the cleaned intramedullary canals of femur and tibia. Rods are joined at the joint line with a connector and joint space is filled with more bone cement to achieve temporary and very stable arthrodesis.

POSTOPERATIVE MANAGEMENT

Partial weight-bearing and no flexion/extension while spacer is in place; second stage reimplantation as soon as infection is controlled.

RESULTS

Complications related to the spacer were rare (5.3%). Reimplantation of an implant was possible in 95 of 113 patients (84%), of those, 23 (20%) received an arthrodesis. Of the 95 patients that were reimplanted, 14 showed signs of recurrent infection. Mean time to last follow-up was 15.6 months post reimplantation. Mean knee pain was 2.9/10; overall function was good; 6 patients had an extension lag; mean total range of motion was 88°.

Effects of an Integrated Geriatric-Orthopedic Co-management (InGerO) on the Treatment of Older Orthopedic Patients with Native and Periprosthetic Joint Infections

PURPOSE

In view of our aging society, co-management with a geriatrician is becoming increasingly important. While such collaborations have been working successfully in trauma surgery for years, it is still unclear whether they are also helpful for non-trauma patients in orthopedics. The aim of this study was to investigate the effect of such a cooperation in orthopedic non-trauma patients with native and periprosthetic joint infections on the basis of five key areas.

RESULTS

Analysis was carried out with 59 patients "with" and 63 "without" geriatric co-management. In the co-management group, delirium was detected significantly more often (p < 0.001), significantly lower pain intensities were measured at the time of discharge (p < 0.001), transfer ability had clearly improved more (p = 0.04), and renal function was more frequently noted (p = 0.04). No significant differences were found with respect to principal diagnoses, surgical procedures performed, complication rates, pressure ulcer and delirium incidence, operative revisions, or length of inpatient stay.

CONCLUSION

Orthogeriatric co-management in orthopedic patients with native and periprosthetic joint infections and nontraumatic surgery appears to have positive impacts on recognition and treatment of delirium, pain management, transfer performance, and attention to renal function. Further studies should follow in order to conclusively assess the value of such co-management in orthopedic nontraumatic surgery patients.

Femoral defects in revision hip arthroplasty: a therapy-oriented classification

INTRODUCTION

The complex field of femoral defects in revision hip arthroplasty displays a lack of standardized, intuitive pre- and intraoperative assessment. To address this issue, the femoral defect classification (FDC) is introduced to offer a reliable, reproducible and an intuitive classification system with a clear therapeutic guideline.

MATERIALS AND METHODS

The FDC is based on the integrity of the main femoral segments which determine function and structural support. It focuses on the femoral neck, the metaphysis consisting of the greater and lesser trochanter, and the femoral diaphysis. The four main categories determine the location of the defect while subcategories a, b and c are being used to classify the extent of damage in each location. In total, 218 preoperative radiographs were retrospectively graded according to FDC and compared to intraoperatively encountered bone defects. To account for inter-rater and intra-rater agreement, 5 different observers evaluated 80 randomized cases at different points in time.

RESULTS

A Cohens kappa of 0.832 ± 0.028 could be evaluated, accounting for excellent agreement between preoperative radiographs and intraoperative findings. To account for inter-rater reliability, 80 patients have been evaluated by 5 different observers. Testing for inter-rater reliability, a Fleiss Kappa of 0.688 could be evaluated falling into the good agreement range. When testing for intra-rater reliability, Cohens Kappa of each of the 5 raters has been analyzed and the mean was evaluated at 0.856 accounting for excellent agreement.

CONCLUSION

The FDC is a reliable and reproducible classification system. It combines intuitive use and structured design and allows for consistent preoperative planning and intraoperative guidance. A therapeutic algorithm has been created according to current literature and expert opinion. Due to the combination of the FDC with the recently introduced Acetabular Defect Classification (ADC) a structured approach to the entire field of hip revision arthroplasty is now available.

[Reconstruction of the extensor apparatus with advanced structural defects in knee revision arthroplasty]

OBJECTIVE

Restoration of the extensor apparatus in the case of advanced tendon defects as part of revision total knee arthroplasty (TKA). Reconstruction and augmentation using vascularized gastrocnemius muscle and tendon.

INDICATIONS

Advanced degeneration of the extensor apparatus (patella tendon; quadriceps tendon) with or without discontinuity, following revision arthroplasty.

CONTRAINDICATIONS

Persistent infection or pending TKA revision. Damaged gastrocnemius or soleus muscle or Achilles tendon.

SURGICAL TECHNIQUE

Extension of the surgical TKA-access medial-distally. Separation of the medial gastrocnemius muscle along the raphe and preparation of the distal tendon from the soleus portion. Transposition into the defect site, augmentation or reconstruction of the defect by double turn of the gastrocnemius tendon. The muscle belly serves to adequately cover the tendon as well as the ventral knee joint. Mesh coverage of the muscle.

POSTOPERATIVE MANAGEMENT

Immobilization of the knee and ankle for 10 days until mesh graft healing. Stepwise increasing flection of the knee with 30°/60°/90° every 2 weeks. Total weight bearing with secured full extended knee, no weight bearing with flexed knee for 6 weeks.

RESULTS

In 9 patients, 3 with complete rupture of the patellar tendon, 5 with destruction of the extensor apparatus, and 1 patient with rupture of the quadriceps tendon following TKA revision, good functional results were achieved with active extension of the knee joint and standing/gait stability 6 months after surgery.

sCD28, sCD80, sCTLA-4, and sBTLA Are Promising Markers in Diagnostic and Therapeutic Approaches for Aseptic Loosening and Periprosthetic Joint Infection

Aseptic prosthetic loosening and periprosthetic joint infections (PJI) are among the most frequent complications after total knee/hip joint arthroplasty (TJA). Current research efforts focus on understanding the involvement of the immune system in these frequent complications. Different immune cell types have already been implicated in aseptic prosthetic loosening and PJI. The aim of this study was to systematically analyze aspirates from knee and hip joints, evaluating the qualitative and quantitative composition of soluble immunoregulatory markers, with a focus on co-inhibitory and co-stimulatory markers. It has been shown that these molecules play important roles in immune regulation in cancer and chronic infectious diseases, but they have not been investigated in the context of joint replacement. For this purpose, aspirates from control joints (i.e., native joints without implanted prostheses), joints with TJA (no signs of infection or aseptic loosening), joints with aseptic implant failure (AIF; i.e., aseptic loosening), and joints with PJI were collected. Fourteen soluble immunoregulatory markers were assessed using bead-based multiplex assays. In this study, it could be shown that the concentrations of the analyzed immunoregulatory molecules vary between control, TJA, AIF, and PJI joints. Comparing TJA patients to CO patients, sCD80 was significantly elevated. The marker sBTLA was significantly elevated in AIF joints compared to TJA joints. In addition, a significant difference for eight markers could be shown when comparing the AIF and CO groups (sCD27, sCTLA-4, sCD137, sCD80, sCD28, sTIM-3, sPD-1, sBTLA). A significant difference was also reached for nine soluble markers when the PJI and CO groups were compared (sLAG-3, sCTLA-4, sCD27, sCD80, sCD28, sTIM-3, sPD-1, IDO, sBTLA). In summary, the analyzed immunoregulatory markers could be useful for diagnostic purposes as well as to develop new therapeutic approaches for AIF and PJI.

Evaluation of the Feasibility of a Telemedical Examination of the Hip and Pelvis - Early Lessons from the COVID-19 Pandemic

Introduction Due to the current COVID-19 pandemic, the German Health Ministry has issued restrictions applying to the field of orthopaedics and trauma surgery. Besides postponement of elective surgeries, outpatient consultations have been drastically reduced. Parallel to these developments, an increase in telemedical consultations has reflected efforts to provide sufficient patient care. This study aims to evaluate the feasibility of a clinical examination of the hip joint and pelvis by way of a telemedical consultation.

Materials and Methods Twenty-nine patients of a German university clinic were recruited and assessed in both telemedical and conventional examinations. Agreement between the two examinations was then assessed, and connections between the observed agreement and patient-specific factors such as age, BMI and ASA classification were investigated.

Results The inspections agreed closely with a mean Cohenʼs kappa of 0.76 ± 0.37. Palpation showed adequate agreement with a mean Cohenʼs kappa of 0.38 ± 0.19. Function showed good agreement with a mean Cohenʼs kappa of 0.61 ± 0.26 and range of motion showed adequate agreement with a mean Cohenʼs kappa of 0.36 ± 0.19. A significant positive correlation was observed between the number of deviations in the different examinations and age (p = 0.05), and a significant positive correlation was shown between the number of non-feasible examinations and age (p < 0.01), BMI (p < 0.01) and ASA classification score (p < 0.01).

Discussion Inspection and function can be reliably evaluated, whereas the significance of palpation, provocation and measurement of range of motion is limited. The small sample size puts limitations on the significance of a statistically relevant correlation between patient-specific factors such as age, BMI and ASA classification score and valid and successful implementation of a telemedical examination. The authors recommend targeted patient selection. If, however, patients are being evaluated who are very old (> 75 years), obese (BMI > 30) or with multiple comorbidities (ASA 3 and above), caution is advised. Large, prospective studies are needed in the future to fully validate telemedical consultations in the fields of orthopaedics and trauma surgery.

Conclusion A telemedical examination of the hip joint and pelvis can be performed with certain limitations. Patient-specific factors such as age, BMI, and extent of comorbidities appear to have a relevant impact on validity and execution of the examination. Patients with multiple comorbidities (ASA 3 and above), advanced age (> 75 years) or obesity (BMI > 30) should, whenever possible, be examined in a conventional outpatient setting.

Basic Clinical Examination of the Foot and Ankle

Successful treatment of foot and ankle diseases requires an accurate diagnosis. In addition to differentiated history taking, clinical examination is the most important component in the diagnosis of foot and ankle diseases. The present video explains the common provocation tests and functional tests that are used in the basic clinical examination of the foot and ankle complex. In addition to general inspection and palpation, the focus is on different diagnostic tests and clinical signs that improve diagnostic accuracy. The present basic clinical examination methods allow a structured approach to clinical issues and can be a good basis, if supplemented by further specific and individual tests.

[Use of an new modular revision arthroplasty system for the knee reconstruction]

OBJECTIVE

Reconstruction of stable knee joint kinematics using modular axis-guided revision implants after failed knee arthroplasty surgery.

INDICATIONS

Revision implant for bone defects (type Anderson Orthopaedic Research Institute [AORI] III) in case of revision arthroplasty. Primary implant in case of mediolateral instability (>grade I) or multidirectional instability.

CONTRAINDICATIONS

Persistent or current joint infection, general infection (e.g. pneumonia), missing metaphysis femoral and/or tibial, insufficient extensor apparatus.

SURGICAL TECHNIQUE

Standard approach extending the previously used skin incision. Arthrotomy, synovectomy and collection of multiple samples for microbiological and histopathological analyses. Preparation of the femur with reamers of increasing diameter. Subsequently, a reference stem is anchored and after referencing the correct rotation and joint line height; the femoral osteotomy is performed after fixation of the 5‑in‑1 cutting block. Following the femoral osteotomy, the box of the femoral prosthesis is prepared. In addition, the tibia is prepared using an intramedullary reference system. Level of constraint and additional tibial augmentation is chosen according to the amount of defect bone and according to ligament stability.

POSTOPERATIVE MANAGEMENT

Full load bearing; standard wound control and sterile dressings; limitation of active/passive range of motion only in case of weakened extensor apparatus.

RESULTS

Between 03/2011 and 05/2018, a total of 48 patients underwent revision arthroplasty using the described system. The mean follow-up was 24 months (range 21-35 months). In 30 of the 48 cases, a rotating hinge variant was implanted, while in 18 cases a semiconstrained variant was implanted. Indications to revision arthroplasty: infection (n = 22), aseptic loosening (n = 11), instability (n = 11), periprosthetic fracture (n = 3) and PMMA allergy (n = 1). In 11 cases, revision had to be performed due to persistent infection (n = 6) and aseptic loosening (n = 5): 9 cases could be successful treated by a two-step revision procedure, while in 2 cases it was necessary to perform an arthrodesis. The 2‑year implant survival rate was 77%.

[Reconstruction of tibial metaphyseal defects with artificial components in revision arthroplasty (GenuX MK System)]

OBJECTIVE

Restoration of knee function by using tibial metaphyseal components in advanced metaphyseal bone defects after multiple bone-damaging revision surgery on the knee joint.

INDICATIONS

Advanced tibial metaphyseal bone defects (Anderson Orthopaedic Research Institute [AORI] IIb and III defects) in revision arthroplasty of the knee joint.

CONTRAINDICATIONS

Persistent or current joint infection, general infection (e.g., pneumonia), nonreconstructable insufficient extensor apparatus.

SURGICAL TECHNIQUE

Standard access including existing skin scars, arthrotomy, removal of cement spacer if necessary and removal of multiple tissue samples; preparation of femur first, followed by preparation of the tibia. Referencing the tibial rotation and joint line height. Tibial osteotomy referenced intramedullarily. Determination of the metaphyseal defect size and choice of component size. Positioning of the rasp guide for the preparation of the metaphyseal component (sleeve); gradual preparation of the bed for the metaphyseal component. Afterwards the prepared component at the desired depth (when using augments +5 or +10 mm accordingly 5 or 10 mm above the tibial plateau) is left and the tibial plateau is fixed on the embedded sleeve. Test coupling, control of the implant position and the height of the joint line radiologically. If satisfactory the definitive implants accordingly to the components of used implants before can be implanted.

POSTOPERATIVE MANAGEMENT

Full weight bearing. Regular wound control; limitation of the degree of flexion only with weakened or reconstructed extensor apparatus.

RESULTS

Between May 2018 and August 2019, 14 metaphyseal tibial components were implanted in 14 patients. The mean follow-up was 10.4 months. The follow-up included clinical examination, KSS (Knee Society Score) and an X‑ray and failure analysis. A significant improvement in range of movement from 75 ± 16° to 100 ± 14° (p < 0.01) was achieved. The KSS improved significantly from 78 ± 12 points preoperatively to 137 ± 23 points postoperatively. Two patients complained of persistent pain after exercise (walking distance >200 m) after 6 months; tibial shaft pain was negated by all patients. The group examined afterwards showed an implant survival rate of 100% in the observation interval.

Difficult-to-treat pathogens significantly reduce infection resolution in periprosthetic joint infections

Periprosthetic joint infection (PJI) is a feared complication after arthroplasty. Our hypothesis was that PJI caused by difficult-to-treat (DTT) pathogens has a worse outcome compared with non-DTT PJI. Routine clinical data on 77 consecutive patients with confirmed PJI treated with 2-stage exchange arthroplasty were placed in DTT and non-DTT PJI groups and analyzed. The main outcome variable was that the patient was definitively free of infection after 2 years. We found definitive infection resolution in 31 patients in the DTT group (68.9%) and 28 patients (87.5%) in the non-DTT group (P < 0.05). The necessity for revision surgery until assumed resolution of infection was significantly more frequent in the DTT group with 4.72 ± 3.03 operations versus 2.41 ± 3.02 operations in the non-DTT group (P < 0.05). PJI caused by DTT bacteria is associated with significantly higher numbers of revision operations and significantly inferior definitive infection resolution.

Characterization of synovial fluid from periprosthetic infection in revision total joint arthroplasty by single-molecule microscopy

Periprosthetic joint infection is among the most common and severe complications in total joint arthroplasty. Today, a combination of different methods is used for diagnosis because no single method with sufficient sensitivity and specificity is available. In this study, we explored the usability of single-molecule microscopy to characterize synovial fluid samples from periprosthetic joint infections. Patients (n = 27) that needed revision arthroplasty underwent the routine diagnostic procedures for periprosthetic joint infection of the University Hospital in Bonn. Additionally, the diffusion rate of two probes, dextran and hyaluronan, was measured in small volumes of periprosthetic synovial fluid samples using single-molecule microscopy. To evaluate the suitability of single-molecule microscopy to detect PJI the AUC for both markers was calculated. The diffusion rate of hyaluronan in periprosthetic synovial fluid from patients with septic loosening was faster than in samples from patients with aseptic loosening. Single-molecule microscopy showed excellent diagnostic performance, with an area under the receiver operating characteristic curve of 0.93, and allowed the detection of periprosthetic joint infection in patients that would be challenging to diagnose with current methods. For the first time, single-molecule microscopy was used to detect periprosthetic joint infection. Our results are encouraging to study the value of single-molecule microscopy in a larger patient cohort. The speed and accuracy of single-molecule microscopy can be used to further characterize synovial fluid, potentially allowing intraoperative diagnosis of periprosthetic joint infections in the future.

[Challenges of discharge management in geriatric traumatology : Example of an integrated orthogeriatric service]

BACKGROUND

Geriatric patients are currently responsible for almost one third of all emergency hospital admissions. An increase of 50% is expected in the next decade. This age redistribution poses new challenges for inpatient care and discharge management. The requirements of an orthopedic trauma surgery clinic in the care of this patient group can be clarified with the help of this first collaboratively created geriatric orthopedic trauma surgery complex treatment unit of a university hospital.

OBJECTIVE

What influence do age and delirium have on discharge management, length of inpatient stay and discharge destination in a geriatric cohort?

MATERIAL AND METHODS

All patients who received inpatient treatment as part of the orthopedic trauma surgery geriatric complex treatment (GKB) between May 2017 and December 2019 were evaluated. An analysis of the demographics, length of inpatient stay, discharge destinations and evaluation of the Barthel index collected on admission and discharge, the mini-mental state examination (MMSE) and the geriatric depression scale (GDS) were carried out.

RESULTS

Out of 312 patients, 110 men and 193 women with a median age of 81 years, 77 patients (24.6%) showed delirium when enrolled in the GKB and 39 (12.5%) dementia. Older patients presented more often with delirium than younger people (p = 0.013), especially those aged 70-79 years (p = 0.037). Dementia patients suffered more frequently from postoperative delirium (p < 0.01). The mean hospital stay was 17.79 days (±4.6 days). The GKB was regularly completed in 60.7% of all cases and 39.3% patients dropped out early. Patients with delirium were discharged significantly less often into their own home but into short-term care or nursing homes (p = 0.038). A general correlation between delirium development and the discharge destination was noticeable (p = 0.004).

CONCLUSION

Patients with dementia are more likely to develop delirium postoperatively, which leads to an increase in the length of inpatient stay, an increase in treatment costs and more work for the discharge management team. In addition, the discharge to the patients' home is impaired by delirium, which means that the growing need for places in short-term care and nursing homes also creates socioeconomic burdens.

The Performance of a Dithiothreitol-Based Diagnostic System in Diagnosing Periprosthetic Joint Infection Compared to Sonication Fluid Cultures and Tissue Biopsies

PURPOSE

The aim of this study was to evaluate the performance of a commercially available dithiothreitol (DTT) kit for routine use in diagnosing periprosthetic joint infections (PJIs) in comparison to conventional microbiological tissue specimens and sonication procedures in a maximal care hospital.

METHODS

We applied the DTT system in 40 consecutive cases of revision arthroplasty (23 PJIs and 17 aseptic revisions), with an exchange or a removal of components. The hardware components were split between the DTT system and the conventional sonication procedure. At least three tissue biopsies and a joint fluid specimen were sent for microbiological and histopathological analysis. Data was analysed retrospectively to compare between the different methods.

RESULTS

Cultures of the DTT fluid showed a sensitivity of 65% and specificity of 100%, as referenced to conventional microbiological cultures. Sonication had better sensitivity (75%) but lower specificity (85%). The categorical agreement of DTT cultures compared to sonication fluid cultures was 78% (31/40). Neither pathogen type, infection duration nor antibiotic pretreatment influenced the accuracy of the DTT, but a low pH in the DTT seemed to be associated with false-negative results.

CONCLUSION

DTT was inferior in sensitivity when diagnosing PJIs compared to sonication fluid cultures and tissue biopsies. A low pH in the DTT fluid correlated with false-negative results. Nevertheless, the closed system of the DTT kit avoids contamination and false-positive results, and DTT can be an alternative where sonication is not available.

Preoperative Anaemia in Primary Hip and Knee Arthroplasty

INTRODUCTION

Approximately one in three patients has untreated preoperative anaemia, which in turn is associated with an increased need for transfusion of allogenic red blood cell concentrates (RBC) and complications in the context of a surgical intervention. Here, the prevalence of preoperative and postoperative anaemia as well as their effects on transfusion rate, hospital length of stay and hospital mortality in primary hip and knee arthroplasty has been analysed.

METHODS

From January 2012 to September 2018, 378,069 adult inpatients from 13 German hospitals were analysed on the basis of an anonymized registry. Of these, n = 10,017 patients had a hip and knee joint primary arthroplasty. The primary endpoint was the incidence of preoperative anaemia, which was analysed by the first available preoperative haemoglobin value according to the WHO definition. Secondary endpoints included in-hospital length of stay, number of patients with red blood cell concentrate transfusion, incidence of hospital-acquired anaemia, number of deceased patients, and postoperative complications.

RESULTS

The preoperative anaemia rate was 14.8% for elective knee joint arthroplasty, 22.9% for elective hip joint arthroplasty and 45.0% for duo-prosthesis implantation. Preoperative anaemia led to a significantly higher transfusion rate (knee: 8.3 vs. 1.8%; hip: 34.5 vs. 8.1%; duo-prosthesis: 42.3 vs. 17.4%), an increased red blood cell concentrate consumption (knee: 256 ± 107 vs. 29 ± 5 RBC/1000 patients; hip: 929 ± 60 vs. 190 ± 16 RBC/1000 patients; duo-prosthesis: 1411 ± 98 vs. 453 ± 42 RBC/1000 patients). Pre-operative anaemia was associated with prolonged hospital stay (12.0 [10.0; 17.0] d vs. 11.0 [9.0; 13.0] d; p < 0.001) and increased mortality (5.5% [4.6 - 6.5%] vs. 0.9% [0.7 - 1.2%]; Fisher p < 0.001) compared to non-anaemic patients. In patients aged 80 years and older, the incidence of preoperative anaemia and thus the transfusion rate was almost twice as high as in patients under 80 years of age.

SUMMARY

Preoperative anaemia is common in knee and hip primary arthroplasty and was associated with a relevant increase in red blood cell concentrate consumption. In the context of patient blood management, a relevant potential arises, especially in elective orthopaedic surgery, to better prepare elective patients, to avoid unnecessary transfusions and thus to conserve the valuable resource blood.

The geriatric patient: special aspects of peri-operative management

This article offers a German perspective on orthopaedic management of geriatric populations in higher-income countries.

Specific orthopaedic procedures necessitate a more intensive level of care in older adult patients, especially with co-morbidities, than in younger patients.

During the pre-, peri- and post-operative periods, several aspects such as patient blood management principles improve the outcomes of geriatric patients.

New interdisciplinary geriatric models of care including geriatric and orthopaedic specialties have to be established to take care of the special needs of geriatric patients.

Cite this article: EFORT Open Rev 2019;4 DOI: 10.1302/2058-5241.4.180087

Force plates may be used for dynamic analyses of endoprostheses explantation procedures

The number of hip and knee arthroplasty replacement surgeries is increasing steadily. In combination with demographic aging and the number of periprosthetic complications, this development has lead to the phenomenon where the need for revision surgery is rising. The problem is, that, while implantation procedures of hip arthroplasties are more or less standardized, explantation is a non-standardized task for experienced specialists, due to the unpredictability of the adequate loosening method. The surgeon often only gets to decide on which tools and methods may be applied to detach the prosthesis, only after getting access to the operation site. The time taken to detach the prosthesis is hardly predictable and mainly depends on the surgeons' skills. To gain objective data on the mechanics of explantation, new measurement methods are required. One technical base for studies on revision procedures are standard force plates, available in biomechanics laboratories.

[Obesity in Revision Total Knee Arthroplasty - a Systematic Review and Legal Assessment]

BACKGROUND

In recent years, the incidence of overweight and obesity has increased in the German population. Thus the number of obese patients treated with primary total joint arthroplasty has also increased. It is therefore predicted that the number of obese patients undergoing revision total joint arthroplasty will also increase. Nevertheless almost every manufacturer of commercially available revision arthroplasty implants states in his product safety guarantee that obesity is a relative or absolute contraindication. Data on revision total joint arthroplasty in obese patients are sparse. The aim of this systematic review is to assess the current literature on re-revision rate, infection rate, postoperative clinical outcome, and implant survival rate in obese patients undergoing revision total knee arthroplasty. Moreover, potential legal consequences and aspects are discussed which are essential for the surgeon.

MATERIAL AND METHODS

We conducted a systematic review of the online databases PubMed and identified clinical studies on obesity and overweight in revision total knee arthroplasty. Study quality was assessed using levels of evidence and the modified Jadad score. We also included descriptive data on case numbers, age, gender, height, weight and follow-up time. Current legal aspects were also analysed.

RESULTS/DISCUSSION

Five studies met the inclusion criteria and were included in the systematic review. The average Jadad score was 1, the average level of evidence 3. In two studies, infection and revision occured more often in obese patients. Patients with morbid obesity had a higher risk of wound revision and periprosthetic joint infections. Three studies showed that obese patients had significantly lower scores for clinical outcome measures in function and pain. The legal aspect was not discussed in any of the five studies. Overall, published data are sparse and very heterogeneous. Therefore comparing these five studies is difficult. However, the results of our review suggest that obesity in revision total knee arthroplasty may have a negative influence on reoperation rate, infection rate and postoperative functional outcome. From a legal point of view, potential weight limitations of the implants intented for use have to be part of the oral preoperative discussion. The patient's informed consent has to be received and documented prior to revision total joint arthroplasty.

Factors influencing the success of anterior cruciate ligament repair with dynamic intraligamentary stabilisation

PURPOSE

Primary repair of the anterior cruciate ligament (ACL) has regained interest of clinicians with recent development of novel repair techniques. Dynamic intraligamentary stabilisation was introduced in an attempt to promote healing by shielding cyclic loads acting upon the ACL during the healing phase. The aim of this study was to identify negative factors likely to influence success of this procedure.

METHODS

Between 2009 and 2014, 264 patients with an acute ACL rupture undergoing dynamic intraligamentary stabilisation were included in this study. Patients were evaluated for anterior/posterior laxity; range of motion and patient reported outcome measures. Adverse events and re-operations were noted. Failure was defined as AP Translation >3 mm, re-rupture or conversion to ACL reconstruction. Minimum follow-up was 24 months. Univariate and multivariate regression models were utilized to determine predictors of failure.

RESULTS

An overall complication rate of 15.1% was noted comprising 9.5% (n = 25) re-ruptures, 4.1% (n = 11) persistent instability, and 1.5% (n = 4) > 10° fixed flexion deformity. Two factors were identified as negative predictors of failure: (1) pursuit of competitive sport activities with a Tegner pre-injury score >7 (Odds Ratio (OR) 4.4, CI 1.2-15.9, p = 0.02) and (2) mid-substance ACL rupture location (OR 2.5, 1.1-5.7, p = 0.02). When neither of those risk factors occurred the failure rate was limited to 3.9%.

CONCLUSIONS

Correct patient selection and narrowing of indications are necessary to maintain high success rates of the procedure. Mid-substance ACL ruptures and a high pre-injury sports activity level are two predictors of inferior outcome.

LEVEL OF EVIDENCE

II.

Indication Criteria for Total Knee Arthroplasty in Patients with Osteoarthritis - A Multi-perspective Consensus Study

Background and Objectives Knee osteoarthritis (OA) is a significant public health burden. Rates of total knee arthroplasty (TKA) in OA vary substantially between geographical regions, most likely due to the lack of standardised indication criteria. We set out to define indication criteria for the German healthcare system for TKA in patients with knee OA, on the basis of best evidence and transparent multi-stakeholder consensus. Methods We undertook a complex mixed methods study, including an iterative process of systematic appraisal of existing evidence, Delphi consensus methods and stakeholder conferences. We established a consensus panel representing key German national societies of healthcare providers (orthopaedic surgeons, rheumatologists, pain physicians, psychologists, physiotherapists), payers, and patient representatives. A priori defined consensus criteria were at least 70% agreement and less than 20% disagreement among the consensus panel. Agreement was sought for (1) core indication criteria defined as criteria that must be met to consider TKA in a normal patient with knee OA, (2) additional (not obligatory) indication criteria, (3) absolute contraindication criteria that generally prohibit TKA, and (4) risk factors that do not prohibit TKA, but usually do not lead to a recommendation for TKA. Results The following 5 core indication criteria were agreed within the panel: 1. intermittent (several times per week) or constant knee pain for at least 3 - 6 months; 2. radiological confirmation of structural knee damage (osteoarthritis, osteonecrosis); 3. inadequate response to conservative treatment, including pharmacological and non-pharmacological treatment for at least 3 - 6 months; 4. adverse impact of knee disease on patient's quality of life for at least 3 - 6 months; 5. patient-reported suffering/impairment due to knee disease. Additional indication criteria, contraindication criteria, and risk factors for adverse outcome were also agreed by a large majority within the multi-perspective stakeholder panel. Conclusion The defined indication criteria constitute a prerequisite for appropriate provision of TKA in patients with knee OA in Germany. In eligible patients, shared-decision making should eventually determine if TKA is performed or not. The next important steps are the implementation of the defined indication criteria, and the prospective investigation of predictors of success or failure of TKA in the context of routine care provision in Germany.

RANK-ligand and osteoprotegerin as biomarkers in the differentiation between periprosthetic joint infection and aseptic prosthesis loosening

AIM

To assess serum levels of RANK-ligand (RANKL) and osteoprotegerin (OPG) as biomarkers for periprosthetic joint infection (PJI) and compare their accuracy with standard tests.

METHODS

One hundred and twenty patients presenting with a painful total knee or hip arthroplasty with indication for surgical revision were included in this prospective clinical trial. Based on standard diagnostics (joint aspirate, microbiological, and histological samples) and Musculoskeletal Infection Society consensus classification, patients were categorized into PJI, aseptic loosening, and control groups. Implant loosening was assessed radiographically and intraoperatively. Preoperative serum samples were collected and analyzed for RANKL, OPG, calcium, phosphate, alkaline phosphatase (AP), and the bone-specific subform of AP (bAP). Statistical analysis was carried out, testing for significant differences between the three groups and between stable and loose implants.

RESULTS

All three groups were identical in regards to age, gender, and joint distribution. No statistically significant differences in the serum concentration of RANKL (P = 0.16) and OPG (P = 0.45) were found between aseptic loosening and PJI, with a trend towards lower RANKL concentrations and higher OPG concentrations in the PJI group. The RANKL/OPG ratio was significant for the comparison between PJI and non-PJI (P = 0.005). A ratio > 60 ruled out PJI in all cases (specificity: 100%, 95%CI: 89, 11% to 100.0%) but only 30% of non-PJI patients crossed this threshold. The positive predictive value remained poor at any cut-off. In the differentiation between stable and loose implants, none of the parameters measured (calcium, phosphate, AP, and bAP) showed a significant difference, and only AP and bAP measurements showed a tendency towards higher values in the loosened group (with P = 0.09 for AP and P = 0.19 for bAP).

CONCLUSION

Lower RANKL and higher OPG concentrations could be detected in PJI, without statistical significance.

Single Molecule Microscopy Reveals an Increased Hyaluronan Diffusion Rate in Synovial Fluid from Knees Affected by Osteoarthritis

Osteoarthritis is a common and progressive joint disorder. Despite its widespread, in clinical practice only late phases of osteoarthritis that are characterized by severe joint damage are routinely detected. Since osteoarthritis cannot be cured but relatively well managed, an early diagnosis and thereby early onset of disease management would lower the burden of osteoarthritis. Here we evaluated if biophysical parameters of small synovial fluid samples extracted by single molecule microscopy can be linked to joint damage. In healthy synovial fluid (ICRS-score < 1) hyaluronan showed a slower diffusion (2.2 μm²/s, N = 5) than in samples from patients with joint damage (ICRS-score > 2) (4.5 μm²/s, N = 16). More strikingly, the diffusion coefficient of hyaluronan in healthy synovial fluid was on average 30% slower than expected by sample viscosity. This effect was diminished or missing in samples from patients with joint damage. Since single molecule microscopy needs only microliters of synovial fluid to extract the viscosity and the specific diffusion coefficient of hyaluronan this method could be of use as diagnostic tool for osteoarthritis.

Can 3D ultrasound identify trochlea dysplasia in newborns? Evaluation and applicability of a technique

Femoro-patellar dysplasia is considered as a significant risk factor of patellar instability. Different studies suggest that the shape of the trochlea is already developed in early childhood. Therefore early identification of a dysplastic configuration might be relevant information for the treating physician. An easy applicable routine screening of the trochlea is yet not available. The purpose of this study was to establish and evaluate a screening method for femoro-patellar dysplasia using 3D ultrasound. From 2012 to 2013 we prospectively imaged 160 consecutive femoro-patellar joints in 80 newborns from the 36th to 61st gestational week that underwent a routine hip sonography (Graf). All ultrasounds were performed by a pediatric radiologist with only minimal additional time to the routine hip ultrasound. In 30° flexion of the knee, axial, coronal, and sagittal reformats were used to standardize a reconstructed axial plane through the femoral condyle and the mid-patella. The sulcus angle, the lateral-to-medial facet ratio of the trochlea and the shape of the patella (Wiberg Classification) were evaluated. In all examinations reconstruction of the standardized axial plane was achieved, the mean trochlea angle was 149.1° (SD 4.9°), the lateral-to-medial facet ratio of the trochlea ratio was 1.3 (SD 0.22), and a Wiberg type I patella was found in 95% of the newborn. No statistical difference was detected between boys and girls. Using standardized reconstructions of the axial plane allows measurements to be made with lower operator dependency and higher accuracy in a short time. Therefore 3D ultrasound is an easy applicable and powerful tool to identify trochlea dysplasia in newborns and might be used for screening for trochlea dysplasia.

Dynamic intraligamentary stabilization and primary repair: a new concept for the treatment of knee dislocation

BACKGROUND

Traumatic knee dislocation represents a rare but devastating injury. Several controversies persist regarding type of treatment, surgical timing, graft selection, repair versus reconstruction of the medial and lateral structures, surgical techniques and postoperative rehabilitation. A new technique for primary ACL stabilization, dynamic intaligamentary stabilization (DIS) was developed at the authors' institution. The purpose of this study was to analyze the clinical and radiological outcomes of surgically treated traumatic knee dislocations by means of the DIS technique for the ACL, primary suturing for PCL, MCL and LCL.

METHODS

Between 2009 and 2012, 35 patients treated surgically for traumatic knee dislocation with primary anterior cruciate ligament (ACL) reconstruction with DIS, suturing of the posterior cruciate ligament (PCL) and primary complete repair of collaterals, were evaluated clinically (IKDC score, SF12 health survey, Lysholm score, Tegner score) and radiologically with a mean follow up of 2.2 years (range 1.00-3.50 years) years. Instrumented anterior-posterior translation was measured (KT-2000).

RESULTS

Anterior/posterior translation (KT-2000) for the healthy and injured limb was 4.8mm (range 3-8mm) and 7.3mm (range 5-10) (89N) respectively. Valgus and varus stress testing in 30° flexion was normal in 26 (75%) and 29 (83%) patients, respectively. The IKDC score was B in 29 (83%) and C in 6 (17%) patients, while the mean Tegner score was 6 (range 4-8). The mean Lysholm score was 90.83 (range 81-95) and mean SF-12 physical and mental scores were 54.1 (range 45-60) and 51.0 (range 39-62) respectively. In 2 patients, a secondary operation was performed.

CONCLUSIONS

Early, one stage reconstruction with DIS can achieve good functional results and patient satisfaction with overall restoration of sports and working capacity without graft requirements.

Acetabular defect reconstruction in revision hip arthroplasty with a modular revision system and biological defect augmentation

PURPOSE

Revision of failed total hip arthroplasty with severe acetabular bone loss represents a rare but challenging problem. Anatomic reconstruction with biological defect augmentation as solid bone transplants or cancellous bone restores bone stock while providing good component stability. The objective of this study was to present short- to mid-term results of revision total hip arthroplasty with a modular ring system in a consecutive series of patients with severe acetabular bone loss.

METHODS

We retrospectively reviewed 39 consecutive patients (39 hips) with severe acetabular bone loss (Paprosky type 3 A and 3 B) reconstructed with revision total hip arthroplasty using the cementless modular ring system MRS-Titan®. The MRS-Titan® consists of independent ring systems that are adapted modularly to the defect situation. Combined with acetabular defect reconstruction by using cancellous bone in impaction grafting technique, the MRS-Titan® system offers a cement-free revision system that enables defect-adapted customization to individual anatomic matters, bridging of the acetabular bone defect and reconstruction of the centre of rotation. Initial stability of the implant was obtained by screw fixation. Harris hip score and sequential radiographs were used to evaluate clinical and radiographic results.

RESULTS

At an average follow up of 31 months (range 12-69 months) 33 of 39 (84.6 %) of the implants were considered radiographically stable without signs of acetabular migration of more than 2 mm in the horizontal or vertical direction, implant rotation or screw breakage. Complications included six implant failures (15 %). We recorded one aseptic loosening of the MRS prosthesis after 20 months. Five patients (12.8 %) had to undergo revision surgery because of periprosthetic joint infection. Two patients had a dislocation postoperatively. The mean Harris hip score improved from 27 ± 14 points preoperatively to 76 ± 15 points at the time of last follow up.

CONCLUSION

By achieving stable implant fixation and providing potential for biological fixation, treatment of severe acetabular bone loss in revision total hip arthroplasty with the modular ring system MRS-Titan provides a durable solution with good clinical and radiographic results and allows us to accomplish major goals of reconstruction.

Evidence of MRSE on a gentamicin and vancomycin impregnated polymethyl-methacrylate (PMMA) bone cement spacer after two-stage exchange arthroplasty due to periprosthetic joint infection of the knee

BACKGROUND

Periprosthetic joint infections (PJI) are often treated by two stage exchange with the use of an antibiotic impregnated spacer. Most of the two-stage exchange algorithms recommend the implantation of an antibiotic-impregnated spacer during the first stage for a period of 2-24 weeks before reimplantation of the new prosthesis. For the spacer to have a therapeutic effect, the local antibiotic concentration must be greater than the minimal inhibition concentration (MIC) against the pathogens causing the PJI. It must remain so for the entire spacer period, otherwise recurrence of infection or resistances might occur. The question as to whether a sufficient concentration of antibiotics in vivo is reached for the entire spacer period has not been answered satisfactorily.

CASE PRESENTATION

We here present a case of a histologically confirmed chronic PJI 20 month after primary arthroplasty. The primary knee arthroplasty was performed due to osteoarthritis of the joint. Initial assessment did not detect a causative pathogen, and two stage exchange with a vancomycin-gentamycin impregnated spacer was performed. At the time of reimplantation, sonication of the explanted spacer revealed a multi-resistant strain of staphylococcus epidermidis on the device and in the joint. Adaption of the therapy and prolonged treatment successfully eradicated the infection.

CONCLUSION

According to the authors' knowledge, the case presented here confirms for the first time the surface contamination (proven through sonication) of a vancomycin-/gentamicin- impregnated Vancogenx®-spacer with a MRSE after ten weeks of implantation.This case study demonstrates the difficulties still associated with the diagnostics of PJI and the published different two stage treatment regimes with the use of antibiotic impregnated spacers.

Mid-term results of transphyseal anterior cruciate ligament reconstruction in children and adolescents

BACKGROUND

Optimal therapy for anterior cruciate ligament (ACL) rupture in the paediatric population still provokes controversy. Although conservative and operative treatments are both applied, operative therapy is slightly favored. Among available surgical techniques are physeal-sparing reconstruction and transphyseal graft fixation. The aim of this study was to present our mid-term results after transphyseal ACL reconstruction.

METHODS

Fifteen young patients (mean age=12.8±2.6, range=6.2-15.8 years, Tanner stage=2-4) with open physis and traumatic anterior cruciate rupture who had undergone transphyseal ACL reconstruction with unilateral quadriceps tendon graft were prospectively analyzed. All children were submitted to radiological evaluation to determine the presence of clearly open growth plates in both the distal femur and proximal tibia. Postoperatively, all patients were treated according to a standardized rehabilitation protocol and evaluated by radiographic analysis and the Lysholm-Gillquist and IKDC 2000 scores. Their health-related quality of life was measured using the SF-12 PCS (physical component summary) and MCS (mental component summary) questionnaires.

RESULTS

Mean postoperative follow-up was 4.1 years. Mean Lysholm-Gillquist score was 94.0. Thirteen of the 15 knees were considered nearly normal on the IKDC 2000 score. The mean SF-12 questionnaire score was 54.0±4.8 for SF-12 PCS and 59.1±3.7 for SF-12 MCS. No reruptures were observed. Radiological analysis detected one knee with valgus deformity. All patients had a normal gait pattern without restrictions.

CONCLUSION

Transphyseal reconstruction of the anterior cruciate ligament shows satisfactory mid-term results in the immature patient.

Cement-augmented anterior screw fixation of Type II odontoid fractures in elderly patients with osteoporosis

BACKGROUND CONTEXT

Closed reduction and internal fixation by an anterior approach is an established option for operative treatment of displaced Type II odontoid fractures. In elderly patients, however, inadequate screw purchase in osteoporotic bone can result in severe procedure-related complications.

PURPOSE

To improve the stability of odontoid fracture screw fixation in the elderly using a new technique that includes injection of polymethylmethacrylat (PMMA) cement into the C2 body.

STUDY DESIGN

Retrospective review of hospital and outpatient records as well as radiographs of elderly patients treated in a university hospital department of orthopedic surgery.

PATIENT SAMPLE

Twenty-four elderly patients (8 males and 16 females; mean age, 81 years; range, 62-98 years) with Type II fractures of the dens.

OUTCOME MEASURES

Complications, cement leakage (symptomatic/asymptomatic), operation time, loss of reduction, pseudarthrosis and revision surgery, patient complaints, return to normal activities, and signs of neurologic complications were all documented.

METHODS

After closed reduction and anterior approach to the inferior border of C2, a guide wire is advanced to the tip of the odontoid under biplanar fluoroscopic control. Before the insertion of one cannulated, self-drilling, short thread screws, a 12 gauge Yamshidi cannula is inserted from anterior and 1 to 3 mL of high-viscosity PMMA cement is injected into the anteroinferior portion of the C2 body. During polymerization of the cement, the screws are further inserted using a lag-screw compression technique. The cervical spine then is immobilized with a soft collar for 8 weeks postoperatively.

RESULTS

Anatomical reduction of the dens was achieved in all 24 patients. Mean operative time was 64 minutes (40-90 minutes). Early loss of reduction occurred in three patients, but revision surgery was indicated in only one patient 2 days after primary surgery. One patient died within the first eight postoperative weeks, one within 3 months after surgery. In five patients, asymptomatic cement leakage was observed (into the C1-C2 joint in three patients, into the fracture in two). Conventional radiologic follow-up at 2 and 6 months confirmed anatomical healing in 16 of the 19 patients with complete follow-up. In two patients, the fractures healed in slight dorsal angulation; one patient developed a asymptomatic pseudarthrosis. All patients were able to resume their pretrauma level of activity.

CONCLUSIONS

Cement augmentation of the screw in Type II odontoid fractures in elderly patients is technically feasible in a clinical setting with a low complication rate. This technique may improve screw purchase, especially in the osteoporotic C2 body.

[Operative treatment of congenital hip osteoarthritis with high hip luxation (Crowe type IV)]

OBJECTIVE

The aim of the therapy is mechanical and functional stabilization of high dislocated hips with dysplasia coxarthrosis using total hip arthroplasty (THA).

INDICATIONS

Developmental dysplasia of the hip (DDH) in adults, symptomatic dysplasia coxarthrosis, high hip dislocation according to Crowe type III/IV, and symptomatic leg length inequality.

CONTRAINDICATIONS

Cerebrospinal dysfunction, muscular dystrophy, apparent disturbance of bone metabolism, acute or chronic infections, and immunocompromised patients.

SURGICAL TECHNIQUE

With the patient in a lateral decubitus position an incision is made between the anterior border of the gluteus maximus muscle and the posterior border of the gluteus medius muscle (Gibson interval). Identification of the sciatic nerve to protect the nerve from traction disorders by visual control. After performing trochanter flip osteotomy, preparation of the true actetabulum if possible. Implantation of the reinforcement ring, preparation of the femur and if necessary for mobilization, resection until the trochanter minor. Test repositioning under control of the sciatic nerve. Finally, refixation of the trochanteric crest.

POSTOPERATIVE MANAGEMENT

During hospital stay, intensive mobilization of the hip joint using a continuous passive motion machine with maximum flexion of 70°. No active abduction and passive adduction over the body midline. Maximum weight bearing 10-15 kg for 8 weeks, subsequently, first clinical and radiographic follow-up and deep venous thrombosis prophylaxis until full weight bearing.

RESULTS

From 1995 to 2012, 28 THAs of a Crow type IV high hip-dislocation were performed in our institute. Until now 14 patients have been analyzed during a follow-up of 8 years in 2012. Mid-term results showed an improvement of the postoperative clinical score (Merle d'Aubigné score) in 86 % of patients. Good to excellent results were obtained in 79 % of cases. Long-term results are not yet available. In one case an iatrogenic neuropraxia of the sciatic nerve was observed and after trauma a redislocation of the arthroplasty appeared in another case. In 2 cases an infection of the THA appeared 8 and 15 months after index surgery. No pseudoarthrosis of the trochanter or aseptic loosening was noticed.

The cement prosthesis-like spacer: an intermediate halt on the road to healing

BACKGROUND

Periprosthetic infections remain a devastating problem in the field of joint arthroplasty. In the following study, the results of a two-stage treatment protocol for chronic periprosthetic infections using an intraoperatively molded cement prosthesis-like spacer (CPLS) are presented.

METHODS

Seventy-five patients with chronically infected knee prosthesis received a two-stage revision procedure with the newly developed CPLS between June 2006 and June 2011. Based on the microorganism involved, patients were grouped into either easy to treat (ETT) or difficult to treat (DTT) and treated accordingly. Range of motion (ROM) and the knee society score (KSS) were utilized for functional assessment.

RESULTS

Mean duration of the CPLS implant in the DTT group was 3.6 months (range 3-5 months) and in the ETT group 1.3 months (range 0.7-2.5 months). Reinfection rates of the final prosthesis were 9.6% in the ETT and 8.3% in the DTT group with no significant difference between both groups regarding ROM or KSS (P = 0.87, 0.64, resp.).

CONCLUSION

The results show that ETT patients do not necessitate the same treatment protocol as DTT patients to achieve the same goal, emphasizing the need to differentiate between therapeutic regimes. We also highlight the feasibility of CLPS in two-stage protocols.

Hip resurfacing using a modified lateral approach with limited splitting of the gluteus medius muscle results in significant impairment of hip abductor strength

BACKGROUND

A lateral, transgluteal approach for hip resurfacing carries the risk of approach-related weakening of the hip abductors due to unsuccessful re-adaptation of the gluteal muscles to the greater trochanter or to injury to the inferior nerve branch of the superior gluteal nerve.

OBJECTIVE

We investigated whether hip resurfacing using a soft tissue-sparing, modified transgluteal approach with limited cranial splitting of the gluteus medius muscle reduces hip abductor strength and the risk of approach-related injury to the superior gluteal nerve.

METHODS

Thirty-one patients (14 female, 17 male; mean age 53.5 ± 5.2 years) underwent hip resurfacing using a modified transgluteal approach with limited cranial splitting of the gluteus medius muscle. Nerve conduction signals were measured by surface electromyography (EMG), hip abductor strength by isokinetic testing a mean 36.2 months (± 11 mos) after surgery. The unoperated side was used as control.

RESULTS

Surface EMG disclosed no neural lesions of the inferior branch of the superior gluteal nerve. Isokinetics revealed a significant reduction in muscle strength on the operated versus the contralateral side.

CONCLUSIONS

Even a limited incision of the gluteus medius muscle resulted in significant impairment of hip abductor strength 2.5 years after surgery.

Anterior crucial ligament rupture: self-healing through dynamic intraligamentary stabilization technique

PURPOSE

Surgery involving arthroscopic reconstruction of the injured ligament is the gold standard treatment for torn anterior cruciate ligament (ACL). Recent studies support the hypothesis of biological self-healing of ruptured ACL. The aim of the study is to evaluate, in an animal model, the efficacy of a new technique, dynamic intraligamentary stabilization that utilizes biological self-healing for repair of acute ACL ruptures.

METHODS

The ACL in 11 adult female white alpine sheep was transected and in 8 sheep reconstructed by dynamic intraligamentary stabilization. To enhance the healing potential, microfracturing and collagen were used in all animals. The contralateral, non-operated knees served as controls. At 3 months postkilling, all animals were submitted to magnetic resonance imaging and biomechanical and histological evaluation.

RESULTS

No surgery-related complications were observed. Postoperatively, all animals regularly used the operated leg with full weight bearing and no lameness. At the time of killing, all animals exhibited radiological and histological healing of the transacted ACL. Biomechanical tests confirmed successful restoration of anteroposterior translation in the dynamic intraligamentary stabilization knees. Histological examination revealed dense scar tissue at the ends of the transected ligaments exhibiting hypercellularity and hypervascularization.

CONCLUSION

The dynamic intraligamentary stabilization technique successfully induced self-healing of ruptured ACL in a sheep model. Knee joints remained stable during the healing period allowing free range of motion and full weight bearing, and no signs of osteoarthritis or other intraarticular damage in the follow up were observed.

[Burden and need for psychosocial intervention of glioblastoma patients]

Glioblastoma patients should be provided with a professional health care system that helps reduce their psychosocial burden. The aim of this study was to identify patients in need of psychosocial intervention. In addition, it was examined whether physicians' assessments adequately address the burden patients are under and their need for intervention. During their visit to one of two neurosurgery outpatient departments, n = 49 glioblastoma patients filled out the short version of the Hornheider questionnaire (HFK). Consulting physicians also rated their patients' burdens in a specially adapted version of the questionnaire (HFK-F). The results of the psychometric evaluation with both instruments were satisfactory. The majority of the patients (76 %) were identified as in need of psychosocial intervention. All of them were correctly categorized with the physicians' ratings. Physicians overestimated some aspects of the patients' burden, particularly in regard to their problems with relaxing and fear of living with the illness. The patients' ratings concerning the quality of the information physicians provided and their overall state of health only corresponded with the physicians' ratings in roughly half of the cases.

An intraoperatively moulded PMMA prostheses like spacer for two-stage revision of infected total knee arthroplasty

We report a series of 16 consecutive total knee arthroplasty (TKA) revision procedures for deep infection, treated with a newly developed intraoperatively moulded PMMA cement-prostheses-like spacer (CPLS). The standard treatment consisted of a two-stage protocol with initial explantation of the infected components combined with radical debridement, followed by implantation of a temporary cement spacer and final reimplantation of a new TKA. A sterilizeable Teflon tapered aluminium mould was developed for production of a custom made CPLS during the intervention. Stable implantation of the CPLS was achieved with a second cementation, allowing for correct alignment and ligament balancing. The spacer remained 3.5 months on average until reimplantation of a TKA occurred. At time of reimplantation, patients had an average KSS score of 84.44 points with an average flexion capacity of 102°. There was no recurrent infection during the study period of minimum 2 years. With this new technique, a low friction articulation with good stability, high comfort and a better range of motion compared to handcrafted spacers was achieved. The use of this spacer is a time sparing, cheap and convenient option in 2-stage TKA revision.